Integrated filter optical package

Patent metadata

Field	Value
Publication number	US-12364052-B2
Application number	US-201916539442-A
Country	US
Kind code	B2
Filing date	Aug 13, 2019
Priority date	Aug 13, 2019
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

An integrated filter optical package including an ambient light sensor that incorporates an infrared (IR) filter in an integrated circuit (IC) stacked-die configuration is provided. The integrated filter optical package incorporates an infrared (IR) coated glass layer to filter out or block IR light while allowing visible (ambient) light to pass through to a light sensitive die having a light sensor. The ambient light sensor detects an amount of visible light that passes through the IR coated glass layer and adjusts a brightness or intensity of a display screen on an electronic device accordingly so that the display screen is readable.

First claim

What is claimed is:

1. A light sensor comprising:
an epoxy non-optical molding compound having a mounting surface and a non-mounting surface;
electrical terminations disposed in a lead frame around a perimeter of the epoxy non-optical molding compound adjacent to the mounting surface, the electrical terminations being part of the lead frame, wherein each of the electrical terminations of the lead frame includes a first portion having a first thickness and a second portion having a second thickness less than the first thickness;
a light sensitive die embedded in the epoxy non-optical molding compound, wherein a footprint of the light sensitive die overlaps a part of the second portion of at least one electrical termination;
wire bonds embedded in the epoxy non-optical molding compound to electrically connect the light sensitive die to the first portions of the electrical terminations, wherein first ends of respective ones of the wire bonds are attached to the light sensitive die and second ends of the respective ones of the wire bonds are bonded to respective ones of the first portions of the electrical terminations;
an optical film attached to the light sensitive die, the optical film allowing visible light to pass through to the light sensitive die; and
a glass layer coated with an infrared (IR) filter on an exposed surface and on a non-exposed surface of respective opposing sides of the glass layer, the glass layer and the IR filter together forming an IR glass filter that comprises a first coating on the exposed surface of the glass layer and a second coating, separate from the first coating, on the non-exposed surface of the glass layer, the IR glass filter being attached to the optical film and embedded in the epoxy non-optical molding compound where the exposed surface of the IR glass filter is exposed to ambient light and where the IR glass filter is disposed in a non-overlapping arrangement with respect to the second portion of a first one of the electrical terminations on one side of the lead frame and the second portion of a second one of the electrical terminations on an opposing side of the lead frame.

2. The light sensor of claim 1 further comprising a thermal die pad embedded in the epoxy non-optical molding compound adjacent to the mounting surface of the epoxy non-optical molding compound and a die attach film attached to the thermal die pad, wherein the light sensitive die is attached to the thermal die pad via the die attach film.

3. The light sensor of claim 2 , wherein the glass layer is comprised of a homogenous material.

4. The light sensor of claim 3 , wherein the IR glass filter has a footprint smaller than a footprint of the light sensitive die, and wherein the optical film is a die attach film.

5. The light sensor of claim 3 , wherein the optical film is a film over wire material that encapsulates an end of the wire bonds attached to the light sensitive die.

6. The light sensor of claim 1 further comprising a die attach film, wherein the light sensitive die is attached to the second portions of the electrical terminations at each end of the light sensitive die via the die attach film.

7. The light sensor of claim 6 , wherein a coefficient of thermal expansion of the epoxy non-optical molding compound is tuned to closely match a coefficient of thermal expansion of the glass layer and a coefficient of thermal expansion of the lead frame.

8. The light sensor of claim 7 , wherein the IR glass filter has a footprint smaller than a footprint of the light sensitive die, and wherein the optical film is a die attach film.

9. The light sensor of claim 1 , wherein the IR filter is sputter coated onto the glass layer.

10. The light sensor of claim 1 , wherein the epoxy non-optical mold compound includes silica filled mold compounds with coefficient of thermal expansion (CTE) values in a range of 10 ppm below glass transition temperature.

11. The light sensor of claim 1 , wherein a sidewall surface of the IR glass filter includes a sawn texture.

12. The light sensor of claim 1 , further comprising:
a layer of white strip applied over the IR filter coated on the exposed surface.

13. The light sensor of claim 1 , wherein the IR filter comprises a material that is embedded into the glass layer.

14. The light sensor of claim 1 , wherein:
the IR glass filter includes a sidewall surface perpendicular to the non-mounting surface, the sidewall surface having a first portion corresponding to the IR filter coated on the exposed surface, a second portion corresponding to the glass layer, and a third portion corresponding to the IR filter coated on the non-exposed surface; and
the epoxy non-optical molding compound is in contact with the first, second, and third portions of the sidewall surface of the IR glass filter.

15. The light sensor of claim 1 , further comprising a die attach film layer disposed between the light sensitive die and the lead frame and configured to couple the light sensitive die to at least the second portion of the first one of the electrical terminations on the one side of the lead frame and the second portion of the second one of the electrical terminations on the opposing side of the lead frame.

16. The light sensor of claim 15 , wherein the die attach film layer has a footprint which is larger than a footprint of the light sensitive die.

17. An integrated optical filter package comprising:
an epoxy molding compound having a mounting surface and a non-mounting surface;
electrical terminations disposed in a lead frame around a perimeter of the integrated optical filter package adjacent to the mounting surface of the epoxy molding compound, the electrical terminations being part of the lead frame, wherein each of the electrical terminations of the lead frame includes a first portion having a first thickness and a second portion having a second thickness less than the first thickness;
a light sensitive die embedded in the epoxy molding compound, wherein a footprint of the light sensitive die overlaps a part of the second portion of at least one electrical termination;
wire bonds embedded in the epoxy molding compound to electrically connect the light sensitive die to the first portions of the electrical terminations, wherein first ends of respective ones of the wire bonds are attached to the light sensitive die and second ends of the respective ones of the wire bonds are bonded to respective ones of the first portions of the electrical terminations;
an optical film attached to the light sensitive die, the optical film allowing visible light to pass through to the light sensitive die; and
a borosilicate glass layer coated with an infrared (IR) filter on an exposed surface and on a non-exposed surface of respective opposing sides of the borosilicate glass layer, the IR filter and the borosilicate glass layer together forming an IR glass filter that comprises a first coating on the exposed surface of the borosilicate glass layer and a second coating, separate from the first coating, on the non-exposed surface of the borosilicate glass layer, the IR glass filter being attached to the optical film and embedded in the epoxy molding compound where the exposed surface of the IR glass filter is exposed to ambient light and where the IR glass filter is disposed in a non-overlapping arrangement with respect to the second portion of a first one of the electrical terminations on one side of the lead frame and the second portion of a second one of the electrical terminations on an opposing side of the lead frame.

18. The integrated optical

Assignees

• Texas Instruments Inc

Inventors

• Kummerl Steven Alfred
• Jacobs Simon Joshua
• Huckabee James Richard
• Bito Jo
• Zhang Rongwei

Classifications

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/736

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W72/5445

  being orthogonal to a side surface of the chip, e.g. parallel arrangements · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W72/075

  of bond wires · CPC title